1. Field of the Invention
The present application is directed to a folding knife assembly having a blade assembly comprising a fixed blade portion and a movable blade portion, wherein the fixed and moveable blade portions are structured and disposed to interlock with one another when the blade assembly is disposed in an open configuration.
2. Description of the Related Art
Knives are among the oldest and most common tools employed by modern mankind. As such, knives are available in a myriad of shapes, sizes, and designs for a wide variety of functions. As an example, the art related to knives range from large butcher knives for carving meat to tiny precision surgical knives, such as are employed in arthroscopic surgical procedures, with numerous variations in between. Further, given the usefulness of knives for a variety of purposes, folding knives have been developed over the years to make these tools safe for a user to carry on his or her person, yet remain readily available to be deployed when needed.
Typically, folding knives consist of a movable blade that is fixed to some type of pivot point within a handle, the handle being structured to shield the sharpened edge of the knife blade while it is in a closed position for a transport and/or storage. An important variation on the standard folding knife is a folding knife having a lock or stop such that a user must actuate some type of release mechanism in order to free the blade so that it may be moved from an open to a closed position. Some folding knives also incorporate a deployment mechanism, such as a spring assisted opening mechanism, commonly known as spring assisted opening knives or switch-blade knives, however, it is noted that such spring assisted opening mechanisms are illegal in many jurisdictions. A variation of such a spring assisted opening knife is a stiletto type knife, wherein the blade does not fold into the handle, but rather, is deployed lengthwise in and out of one an open end of a knife handle.
As with knives in general, folding knives have been developed for a wide variety of uses. For example, a miniaturize folding knife assembly commonly known as a pen knife are small enough to be carried on a keychain and are utilized for extremely light duty tasks such as cutting string, plastic, tape, etc. At the opposite end of the spectrum, folding knife assemblies employed substantially standard size knife blades made of hardened steel and being structured for heavy duty applications are often used by persons in the construction industry, sportsman, and other such rigorous activities wherein a heavy duty knife assembly is required. Typically, the user of such a large folding knife assembly will utilize a sheath or other holder in order to comfortably and safely carry the knife on his or her person, such as attached to a belt loop, tool belt, or other such article. Between these extremes, are a variety of intermediate sized folding knife assemblies commonly referred to as pocket knives. Once again, these pocket knives typically include a single movable blade which is attached to the handle via pivot member which allows the blade to be opened and closed. In addition, a good number of pocket knives employ some form of lock or stop in order to avoid possible injury to a user as a result of inadvertent closure of the blade while the knife is in use. A significant problem common to all of the folding knives noted above is a utilization of a single blade member which is only secured at one end by a pivot structure, which also serves to attach the blade member to the handle. More in particular, upon rotating the single blade from a closed to an opened position about its pivot point, only a small portion of the single blade member is retained within and supported by the knife handle. As a result, a substantial weak point exists in known folding knives when the blade is deployed in an open configuration, i.e., the weak point being the interface of the single blade member and the handle. In contrast, a fixed handle knife of similar dimensions will include a significant portion of a single fixed blade member, i.e., the tang or shank, being secured between opposing handle members. Thus, a single fixed blade knife assembly provides significantly greater strength and stability to the overall knife blade versus a folding knife assembly of similar dimension, i.e., useable blade length, and materials of construction of the blade, tang, handle, and connecting hardware.
As noted above, a number of folding knives include some form of lock or stop which is designed to retain the blade in an open or closed position until such time as the user actuates the release mechanism. It is also common for folding knives employing such a lock to require two handed operation by the user, more specifically, one hand to grasp the handle and actuate a release mechanism and the other hand to grasp and physically reposition the blade between open and closed positions. It is well known, however, that in many applications, it is not convenient or may not even be possible for a user to have both hands free in order to open and close a folding knife.
As such, it would be beneficial to provide a folding knife assembly which approaches the structural integrity of a single fixed blade knife of comparable dimensions in quality of materials. More in particular, it would be desirable to provide a folding knife assembly wherein a substantial portion of the blade assembly remains fixedly secured to at least a portion of the handle while another portion of the blade is deployed in an open configuration. It would also be helpful to provide such a folding knife assembly wherein deployment of at least the portion of the blade between open and closed configuration may be accomplished using only one hand. Yet another advantage may be realized by incorporating a self cleaning means into a folding knife assembly in order to prevent, or at least minimize the accumulation of dirt or debris from the inner workings of knife assembly so as to minimize maintenance and increase the useable life of the same. It would also be beneficial to provide such a folding knife assembly to comprise a minimal number of moving parts, once again, to minimize the need for maintenance and to assure a long useable life of such as folding knife assembly.